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I've put a lot of 'mods' on my car. This was one, which actually registered on the "butt dyno".
Agreed for sure. The one thing I have left to wonder over is the difference between the 2mm pre load recommended by turbosmart or the 3mm recommended by any other install video I could find. I ended up going with 3mm pre load, but Im unsure which is most beneficial and why.
 

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Agreed for sure. The one thing I have left to wonder over is the difference between the 2mm pre load recommended by turbosmart or the 3mm recommended by any other install video I could find. I ended up going with 3mm pre load, but Im unsure which is most beneficial and why.
IMO, there's very little difference in 1mm.馃槂 I can't answer you for sure (I'll send out the batsignal for @EcoVert17 & @slojas , who if memory serves me correct, played with many different preload settings), but my own reasoning went like this:
A) I figure, the LESS preload space it has, then the more pressure it needs to receive to 'crack'. Since 'cracking' is akin to 'losing power' on the turbo, I went with the lesser.
B) As long as TS said 2mm was okay, I was good with that. I kept a keen eye for overboost after I was done....but nothing....its been absolutely perfect for me.
 

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I've been doing alot of reading of older posts and watching of videos today to try to crack the code lol. The solution I've come to is that I will have to data log to get comparisons as well as just feeling the car out. I will say that right now at 3mm preload the car feels great but I will need to datalog to see if my numbers justify my feeling of the car.
 

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I'm going to back off a turn from 4 to 3 tomorrow. I just datalogged a run that only showed my max hp of 278 and tq of 350. That is well below what I was reading before on logs before the install.
 

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So update: I spent the entire weekend messing with that 7psi waste gate. While the driveability of the car felt greatly improved, I couldn't get more than 21.15 psi and 283 hp and 360 ft lbs according to my AP. Which is greatly reduced from the numbers I was getting pre install with stock waste gate on pro tune. I tried many different pre loads from 1.5mm all the way to 3.5mm to no avail. Only thing I can think is my car just doesn't like turbosmart stuff( I say that because my car didn't like the dual port BOV either). I did however get very proficient at the install/Uninstall of the waste gate. I think I got my average down to about 20 minutes.
 

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So update: I spent the entire weekend messing with that 7psi waste gate. While the driveability of the car felt greatly improved, I couldn't get more than 21.15 psi and 283 hp and 360 ft lbs according to my AP. Which is greatly reduced from the numbers I was getting pre install with stock waste gate on pro tune. I tried many different pre loads from 1.5mm all the way to 3.5mm to no avail. Only thing I can think is my car just doesn't like turbosmart stuff( I say that because my car didn't like the dual port BOV either). I did however get very proficient at the install/Uninstall of the waste gate. I think I got my average down to about 20 minutes.
I'm sorry to hear that you weren't as successful with the 7lb spring. I thought it worked splendidly with the FP tune, but every tune is different to some degree. Just out of curiousity, did the numbers on your AP immediately return to 'normal' when you put the stock back on?
 

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Unsure, I called it quits for the day after re installing the stock waste gate today. I have since however done quite a bit of research and what I get out of it is this. There's a **** load of pre load on the stock waste gate which is why I am able to hit 26.5 psi of boost after having been tuned. Sequentially, the same should be for the turbosmart waste gate. Maybe I needed to use more preload to mimick the boost/power results of the tune and stock waste gate. Ie, each full turn is equivalent to 1mm of pre load and also 1 psi of boost. As I was seeing 21.15 psi on 2 mm pre load(recommended by turbosmart) and 23 on 4 mm(4 full turns) what if I had pre loaded to 5,6,7 mm or 5,6,7 full turns!?!
 

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Another thing of note:
From my understanding, Continuously upping the pressure on the spring by tightening the clevis(while achieving more boost can be had this way) at what point does it create too much stress on the waste gate and a lean fuel condition. It would seem more desirable to achieve target boost by changing springs and keeping pre load at an optimal 2-3mm which also adversely creates the need for further tuning for the increased spring size and proper fuel delivery. From the chart below, if I wanted 26lbs of boost I should up the spring size to a 10 or 12 psi spring.
36811
 

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It reminds me of changing pulleys on a superchararger. There is an acceptable amount of playroom in pulley size to increase boost before you have to retune for the added fuel needed to address even smaller pulleys equating to more boost beyond what the current tune is meant to address.
 

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After checking this morning on a couple of WOT runs everything is back to normal according to numbers I was making tuned w/ bolt ons pre turbosmart waste gate install.
 

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After checking this morning on a couple of WOT runs everything is back to normal according to numbers I was making tuned w/ bolt ons pre turbosmart waste gate install.
So then I think I have my reasoning all wrong on "preload". My thought was that the more "preload" the spring has (meaning, its already into its compression, and compression of spring is what causes the wastegate to 'crack' and eventually fully open), the less ability it has to build boost, since opening the wastegate is akin to 'dumping boost' and you are technically CLOSER to opening the wastegate with more preload, than with less.

Is that true? This was my understanding unless I have it wrong. You are saying MORE preload helps build MORE boost?? Could you explain how? Thanks man.
 

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@Whistler46 Are you custom tuned? That might also be something as to why your results weren't satisfactory. Speak with your tuner. Maybe the wastegate tables are already optimized for a stock wastegate actuator with a lot of preload? Just a thought.
 

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Your not too far off. Pre load is put on the spring prior to installing on the turbo. When installed its already pre loaded and the gate is fully closed. So whatever pressure is on that spring is done so with the gate fully closed position which makes it harder to crack the gate open and spill out excess boost. I had to watch a crap ton of videos on waste gate operation and pre loading, myths and truths, internal vs external types.
 

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@Whistler46 Are you custom tuned? That might also be something as to why your results weren't satisfactory. Speak with your tuner. Maybe the wastegate tables are already optimized for a stock wastegate actuator with a lot of preload? Just a thought.
I absolutely agree. My hopes were to get away with a spring within the acceptable range but I was unwilling to wind up that waste gate to achieve tuned target boost to avoid damage. I am custom tuned by PDtuning.
 

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When installed its already pre loaded and the gate is fully closed. So whatever pressure is on that spring is done so with the gate fully closed position
This fact just finally got me to visualize it the right way! You're preloading it CLOSED! I was thinking about it all wrong. So more preload will require more pressure to get that wastegate open. Hmmm...now I'm wondering if I should tinker with 3 or 4mm...
 

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Yes, in a way increasing pre load mimics the results of a firmer spring. But shouldn't require the same tuning if your air/fuel/spark has already been adjusted for higher boost during tuning. This is my conundrum but I'm too much of a chicken pot pie to try an excessive amount of pre load on a smaller spring(7 psi vs 10-12psi) to achieve what I was already tuned for lol. Just this morning with the stock actuator back in I hit just over 25 psi just WOT to 45.
 

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Yes, in a way increasing pre load mimics the results of a firmer spring. But shouldn't require the same tuning if your air/fuel/spark has already been adjusted for higher boost during tuning. This is my conundrum but I'm too much of a chicken pot pie to try an excessive amount of pre load on a smaller spring(7 psi vs 10-12psi) to achieve what I was already tuned for lol. Just this morning with the stock actuator back in I hit just over 25 psi just WOT to 45.
I might have to take a look at this with more trials and in a bit more detail, with some logs, as you did. My app doesn't calculate HP or Torque, but I should be able to measure peak boost on successive WOTS at a few different preload levels. So essentially, I should see higher 'peak boost' numbers with each successive preload turn? That is, until I possibly cause an overboost condition.
 
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